GN: Remove all_blink target on android builds, it does not work yet

public/BUILD.gn

Index: public/BUILD.gn
diff --git a/public/BUILD.gn b/public/BUILD.gn
index 41d2bac558fed94c40d62420423b2309f2a38a81..fb92488439eeb6c39cb7c008f5b0b2a703b33e6c 100644
--- a/public/BUILD.gn
+++ b/public/BUILD.gn
@@ -2,6 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+if (!is_android) {
+
 group("all_blink") {
   deps = [
     "//third_party/WebKit/Source/core",
@@ -10,6 +12,8 @@ group("all_blink") {
   ]
 }
 
+}
+
 config("blink_headers_config") {
   include_dirs = [ ".." ]
 }